Exegesis of the saying of Allah the Exalted: “But if you do not, and you will not, then fear the Fire whose fuel is men and stones, prepared for the disbelievers.”

That is, if you do not bring a surah like it. When He said: It is a conditional clause that cut off their hopes by His saying: meaning, do not attempt to do it, because this is impossible. The particle "fa" here occurs in the answer to the condition, which is: meaning: If you do not do it, and you do not challenge the Qur'an with its like, then the Fire is your abode; fear the Fire. They did not find anything to protect them from the Fire except to believe in what was revealed to Muhammad (peace and blessings be upon him).
"Which" is a relative pronoun describing the Fire; "fuel" is the subject and "men" is the predicate of the subject. Fuel is what is used to kindle fire, such as firewood, for example, in the fire of this world. In the Hereafter, the fuel of the Fire is men and stones; so the Fire burns them and blazes with them—may Allah grant us safety. Some scholars said: The intended meaning is the stones that are worshipped, meaning idols, because they worship idols; so their idols will be with them in the Fire, as Allah the Exalted said: It was also said: The stones are fiery stones—may Allah protect us from that—which increase the heat of the Fire and do not cool down—may Allah grant us safety. But there is no objection to the meaning being both: the worshipped stones and the kindled stones that Allah the Mighty and Majestic created to be used as fuel for the Fire. "Prepared": the hidden pronoun refers to the Fire, and the one who prepared it is Allah the Exalted. The meaning of preparation is making something ready. And His saying: means for every disbeliever, whether he disbelieved in the message, in the oneness of worship, or in something else.